The present invention relates to the field of micro-electromechanical systems (MEMS), and more particularly, relates to a micro-electromechanical inertial measurement module. The present invention further relates to a triaxial accelerometer.
A micro-electromechanical accelerometer is an MEMS technology-based inertial device for measuring the linear movement acceleration of an object in movement. It has the characteristics of being small in size, high in reliability, low in cost and suitable for mass production. Thus, it has a broad market prospect and can be applied to the fields of consumer electronics, aerospace, automotives, medical equipment and weapons.
At present, the triaxial accelerometer is usually implemented through two manners. The first manner is a patchwork method, in which three single-axis structures are combined together or a dual-axis structure and a single-axis structure are combined to implement measurement of three axial accelerations. The second manner adopts a single structure to implement the measurement of the three axial accelerations. In the single-structure implementation solution, generally, z-axis acceleration is measured by an eccentric structure. As for this solution, not only the z-axis detection movement utilizes the eccentricity of the structure, but also the detection movement of a certain axis (e.g., an x-axis or a y-axis) in the plane will be affected by the eccentricity of the structure, such that the movement of the structure is actually a swinging movement, rather than a linear movement. On one hand, this movement increases the coupling between axes, and on the other hand, the change amount of a capacitor is reduced, thereby greatly reducing the detection accuracy. Moreover, during the detection of y-axis acceleration, the actual movement may be a swinging movement, rather than a linear movement due to this characteristic of the structure, further reducing the detection accuracy.